/**
*      author: Y_Yao
*      created: 2025-04-06 15:21:44
**/

#include<bits/stdc++.h>

#define int LL
using namespace std;
using LL = long long;
const LL LLINF = 9e18;
const int INF = 0x3f3f3f3f;
int n;
const int N = 100 + 7;

void solve()
{
    cin >> n;
    int mx = -INF;
    int mi = INF;
    for(int i = 1;i <= n;i++)
    {
        int x = 0;
        cin >> x;
        mx = max(x,mx);
        mi = min(mi,x);
    }
    cout << mx - mi << endl;
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    int t = 1;
    cin >> t;
    while(t--)
    {
        solve();
    }
    return 0;
}